Apparatus and method for producing a video display

Abstract

A method and apparatus for producing a video display that is especially useful in an article handling system to help control a mechanical arm to move an article into a selected position. A video camera is operated to produce a picture of the article on a video screen. At the same time, force sensor are used to measure forces on the article, and a graphical display of those sensed forces is produced on the view of the article on the video screen.

We claim: 
     
       1. A display apparatus comprising: means to produce a view of an article on a display screen for a period of time;   means to measure, at least at a multitude of times during said period, forces applied to the article during said period; and   graphical display means to impose on said view and during said period, a graphical display illustrating the measured forces, and including means to represent in the graphical display each of the measured forces at a respective time during said period.   
     
     
       2. Display apparatus according to claim 1, wherein the graphical display means includes: means to produce a graphical frame on the display screen and to maintain the graphical frame in a fixed position thereon relative to the view of the article; and   means to produce a multitude of graphical images on the display screen, each of the graphical images representing a respective one of the measured forces and being shown on the screen substantially at the same time said respective one force is measured.   
     
     
       3. Display apparatus according to claim 2, wherein: the measured forces each include first, second, and third mutually orthogonal components;   the graphical frame includes a two-dimensional view of three mutually orthogonal axes; and   the means to produce the graphical images is adapted to produce   i) a first, variable length bar along a first of said axes to represent the magnitude of the first component of the forces applied to the article,   ii) a second, variable length bar along a second of said axes to represent the magnitude of the second component of the forces applied to the article, and   iii) a third, variable length bar along a third of said axes to represent the magnitude of the third component of the forces applied to the article.   
     
     
       4. A method of moving an article into a selected position, comprising: operating a video camera to produce a picture on a video screen showing both the article and the selected position;   moving the article toward and into the selected position;   sensing a force applied to the article; and   graphically displaying on the video screen the sensed force as the article is moved into the selected position.   
     
     
       5. A method according to claim 4, wherein the selected position is adjacent a surface, and said force is a force between the article and the surface. 
     
     
       6. Apparatus for moving an article into a selected position, comprising: a moveable mechanical arm;   arm control means connected to the mechanical arm to operate the arm to grip the article and to carry the article into the selected position;   video display means;   a video camera located adjacent the article and connected to the video display means to produce a picture thereon showing both the article and the selected position;   sensing means to sense a force on the article and to generate a signal indicating the magnitude of the sensed force; and   graphical display means connected to the sensing means to receive said signal therefrom, and connected to the video display means to generate thereon a graphical display of the sensed force.   
     
     
       7. Apparatus according to claim 6, wherein: said force includes first, second, and third mutually orthogonal components; and   the graphical display means includes means to generate on the video display means a graphical display illustrating the magnitude of each of said first, second, and third components.